Inferences of ice-sheet change through geological time rely on environmental proxies, yet these inferences assume an unchanging ice-sheet response to climate. Here, using 500-kyr long ice-sheet simulations, we show that the directionality of ice sheet change depends on the background state of the climate. Under cold atmospheric conditions with high-amplitude glacial–interglacial changes in sub-shelf melt, ice sheets advance during cold phases and retreat as the climate warms. However, under warmer air temperatures with reduced glacial–interglacial ice-shelf melt variability, ice sheets advance during warm phases and retreat during colder periods. Forced with a linearly changing climate, the ice sheet switches from one mode to the other, and a resonant response arises at half the forcing frequency. These findings imply that climate–ice sheet phasing is not constant over time, and suggest that ice sheet behaviour under a future, warmer, climate may be substantially different from today. Gradual cooling or warming of the atmosphere, combined with strong ocean-driven basal melt, could have led to major changes in the periodicity, phasing, and asymmetry of past ice sheet growth and decay, according to an ensemble of 500-kyr long ice sheet simulations.

Major changes in Southern Ocean circulation and Antarctic ice sheet dynamics during the late Cenozoic altered marine productivity and carbon burial, yet their impact on sediment biogeochemical processes remains poorly constrained. Here, we combine geochemical data from three IODP Expedition 382 drill cores in Iceberg Alley (Pirie and Dove Basins, Scotia Sea) with a dynamic diagenetic model to reconstruct sediment biogeochemical evolution from the Miocene to the Pleistocene. A previously unrecognised early Pleistocene reorganisation of sediment biogeochemistry was identified beginning around 1.5–2 Ma, being most pronounced in the Pirie Basin. Across all sites, the reactivity of buried POC rose dramatically around this time, likely reflecting enhanced productivity and reduced oxygen exposure due to higher sedimentation rates. This led to a drawdown of dissolved sulphate, driven by intensified anaerobic degradation of organic matter, and accumulation of pyrite in the upper 100 m. A coeval increase in reactive iron content and reactivity led to anaerobic oxidation of methane using both sulphate and iron as electron acceptors in the Pirie and Dove Basins. As a result, methane concentrations in the sulphate-depleted sections downcore remain remarkably low. These sedimentological changes precede the Mid-Pleistocene Transition (1.25 to 0.7 Ma), but coincide with the expansion of the West Antarctic Ice Sheet, which likely increased the delivery of iron and poorly weathered continental material to the high-latitude Southern Ocean. The major changes observed in the Scotia Sea also correspond with shifts in the opal-to-carbonate ratio in deep marine sediments of the Pacific sector of the Southern Ocean. These findings suggest that enhanced delivery of reactive organic carbon and iron to sediments in the Southern Ocean during the early Pleistocene intensified carbon burial and pyrite formation. These processes may have strengthened long-term carbon sequestration in the Southern Ocean and contributed to declining atmospheric CO2 during late Cenozoic climate evolution.

The coupling between tropical and polar climates is critical to Earth's climate dynamics, yet its long-term evolution remains poorly constrained. The Mid-Brunhes Event (MBE; similar to 430 ka), characterized by intensified interglacial warmth and elevated atmospheric CO2, provides a key test case for understanding how tropical-polar interactions respond to major climatic transitions. Here, we apply End-Member (EM) Modeling and spectral analysis on an 800-kyr high-resolution grain-size record from IODP Site U1537 in the Scotia Sea's Antarctic Zone (AZ), identifying three sediment transport end members: (1) aeolian input linked to the Southern Hemisphere Westerlies (SHW) (EM1, 2-10 mu m); (2) sea ice-rafted debris associated with sea ice transport (EM2, 10-20 mu m); (3) current-sorted particles reflecting Antarctic Circumpolar Current (ACC) hydrodynamics (EM3, 20-53 mu m). After the MBE, EM1 and EM2 shift from eccentricity- and obliquity-dominated pacing toward amplified precessional (similar to 19-23 kyr) variability. We interpret this reorganization as reflecting enhanced post-MBE sensitivity of AZ atmosphere-ice-ocean interactions to low-latitude insolation forcing, potentially mediated by changes in the Southern Hemisphere subtropical jet-westerly wind system that altered dust input, and by ITCZ-related changes in westerly structure that influenced Circumpolar Deep Water upwelling and sea-ice dynamics. These results provide new evidence that the MBE reorganized AZ atmosphere-ice-ocean sensitivity to low-latitude orbital forcing, with implications for how this coupling may evolve under future high-CO2 warming.

Ice-sheet responses to environmental forcing are often framed in terms of temperature thresholds linked to ice-sheet volume. To better capture their potential for abrupt change and feedbacks within the Earth system, a more complete assessment of ice-sheet configuration and dynamics is required. Here we use a coupled ice sheet-ice shelf model to identify three distinct regime types, each with characteristic behaviour independent of ice volume. These regimes are diagnosed from the magnitude and variability of multivariate mass loss using a Shannon entropy-based approach. We find that ice sheets occupy low-entropy, highly predictable states under both warm and cold extremes, but exhibit more variable and less predictable behaviour at intermediate conditions. This bistable regime reflects the path-dependent viability of ice shelves, with transitions occurring under atmospheric temperature changes of less than 2 K, highlighting the sensitivity of ice-sheet regimes to climate.

The Antarctic Circumpolar Current (ACC) exerts substantial control on the physical, chemical, and biological properties of the Southern Ocean, playing a key role in modulating the global carbon cycle and climate. However, the orbital-scale forcing and future changes in the strength and position of the ACC remain elusive. Here, we reconstruct the history of ACC extending back to the Last Interglacial (LIG; 128-113 ka) using sediment cores from the Scotia Sea. Based on high-resolution measurements of sortable silt mean grain size, we find that bottom current speed is synchronized with eccentricity, superimposed by precession. During the LIG when both eccentricity and precession reached their maxima, current speed peaked in the region south of the Southern ACC front, suggesting that the Polar Front shifted ~5° southward. We propose that the low-frequency ACC frontal migration is primarily controlled by eccentricity-driven shifts in the Southern Hemisphere Westerlies, while precession-driven shifts contribute to high-frequency migration. Our findings imply under future orbital-scale scenarios, the ACC position is likely to shift north.

Sedimentary uranium (U) and thorium (Th) isotopes are invaluable proxies to assess bottom water redox conditions, site-specific sediment focusing and vertical rain rates. We investigate if authigenic uranium (aU) can serve as a proxy for bottom water ventilation at International Ocean Discovery Program Site U1537 in the Scotia Sea and we provide Th-normalized vertical rain rates and focusing factors. The presented data set is complemented by bulk sediment delta 234U, porewater U concentrations and biogenic barium. Furthermore, we introduce a method to check temporal variations in the detrital factor for the calculation of aU by comparing measured and modeled delta 234U. We observed partial uranium remobilization in the core for sections older than 70 ka, identified by delta 234U anomalies and porewater U concentrations. During interglacials, the accumulation of aU in the sediment is regulated by the decomposition of substantial quantities of organic matter, ultimately controlled by high export productivity and associated high particulate organic carbon fluxes. Conversely, during glacial times, low export productivity coincides with low aU concentrations, suggesting well-oxygenated bottom waters. However, during the Last Glacial Maximum, a rise in aU likely indicates reduced ventilation, suggesting an absence of Weddell Sea Deep Water and/or enhanced water column stratification between 23 and 17.5 ka.

The interhemispheric relation of deep-water ventilation and surface-ocean productivity may have played a prominent role in past atmospheric CO2 regulation. However, how these processes vary on orbital-millennial timescales remains poorly understood. Here, we present high-resolution proxy data and model simulations on the variability of biological productivity and deep water circulation for the abyssal northwestern Pacific Ocean spanning 20-60 kyr. We found that enhanced surface productivity increased during Heinrich Stadials (HS) and long term, caused by intensified westerly winds and associated dust fertilization, implying CO2 extraction from the atmosphere and increased nutrient supply to the euphotic zone. A similar increase in productivity for the Southern Ocean during Heinrich events implies enhanced upwelling and exhalation of CO2 to the atmosphere, indicative for an interhemispheric carbon cycle seesaw on millennial time scales. However, the longer-term global cooling demonstrates that deep ocean carbon storage and degassing was predominantly modulated by the North Pacific Ocean.

Late Miocene climate evolution provides an opportunity to assess Earth's climate sensitivity to carbon cycle perturbation under warmer-than-modern conditions. Despite its relevance for understanding the climate system, the driving mechanisms underlying profound climate and carbon cycle changes - including the enigmatic Late Miocene cooling from 7 to 5.4 million years ago - remain unclear. Here, we present magnetic and geochemical paleoceanographic proxies from a hydrogenetic ferromanganese crust retrieved in the northwestern Pacific Ocean. Our results indicate a striking 50% surge in deep ocean phosphorus concentrations occurred 7 - 4 million years ago, synchronous with enhanced deep ocean oxygen consumption. Employing a global biogeochemical model, we show that increased continental phosphorus weathering, without a concurrent rise in silicate weathering, contributed to the decline in atmospheric CO2 and associated cooling over the Late Miocene. This suggests a prominent decoupling of phosphorus and silicate weathering during a major carbon cycling event over the last 10 million years.

Diatom microfossils are key environmental indicators and an important proxy in paleoenvironmental reconstructions. Sedimentary ancient DNA (sedaDNA) complements microfossil analysis by detecting poorly preserved diatoms and distinguishing morphologically similar taxa, painting a more detailed picture of the past. However, retrieving diatom sedaDNA in marine environments can be challenging due to trace amounts being preserved in the sediment record. Optimising existing protocols is thus essential to maximise diatom sedaDNA yield. This study compares six methods to determine the best approach for recovering diatom sedaDNA from Antarctic marine sediment cores. The same six samples from two sites - U1536C (West Antarctica) and KC02 (East Antarctica), were extracted. Post shotgun sequencing, the methods were evaluated based on diatom sedaDNA recovery, fragment length, and species diversity. Results showed that method performance in retrieving the highest number of Bacillariophyta (diatom) reads is primarily driven by site (R2 = 0.593, p = 0.001) and sample age (R2 = 0.401, p = 0.001), while the extraction method had minimal influence (R2 = 0.001, p = 0.064). The SiMAG method proved highly effective in U1536C but was entirely ineffective in KC02, where the COM Short method successfully recovered diatom sedaDNA. Other methods, including COM QG, PPKIT, and PB, consistently resulted in low sedaDNA yields. Differences in the diversity and the relative abundance of taxonomic classes were also seen across methods (chi 2 88.04 to 99,664.17). This study serves as a focal point for experiments aiming to maximise diatom sedaDNA recovery enabling accurate reconstructions of Antarctic marine ecosystems.

Under sustained global warming, Arctic climate is projected to become more responsive to changes in North Pacific meridional heat transport as a result of teleconnections between low and high latitudes, but the underlying mechanisms remain poorly understood. Here, we reconstruct subarctic humidity changes over the past 400 kyr to investigate the role of low-to-high latitude interactions in regulating Arctic hydroclimate. Our reconstruction is based on precipitation-driven sediment input variations in the Subarctic North Pacific (SANP), which reveal a strong precessional cycle in subarctic humidity under the relatively low eccentricity variations that dominated the past four glacial-interglacial cycles. Combined with climate model simulations, we highlight that precession drives meridional shifts in the northern rim of the North Pacific Subtropical Gyre (NPSG) and modulates the efficiency of heat and water vapor transfer to the SANP and Arctic regions. Our findings suggest that projections of a northward shift of the NPSG in response to future global warming will lead to wetter conditions in the Arctic Ocean and enhanced sea-ice loss. Subarctic Pacific Ocean sediments and modeling results provide new evidence for precession driving meridional shifts in the North Pacific Subtropical Gyre and modulating the efficiency of heat and water vapor transfer to the Arctic regions.

The Saharo-Arabian Desert is one of the largest biogeographical barriers on Earth, impeding dispersals between Africa and Eurasia, including movements of past hominins. Recent research suggests that this barrier has been in place since at least 11 million years ago 1 . In contrast, fossil evidence from the late Miocene epoch and the Pleistocene epoch suggests the episodic presence within the Saharo-Arabian Desert interior of water-dependent fauna (for example, crocodiles, equids, hippopotamids and proboscideans) 2–6 , sustained by rivers and lakes 7,8 that are largely absent from today’s arid landscape. Although numerous humid phases occurred in southern Arabia during the past 1.1 million years 9 , little is known about Arabia’s palaeoclimate before this time. Here, based on a climatic record from desert speleothems, we show recurrent humid intervals in the central Arabian interior over the past 8 million years. Precipitation during humid intervals decreased and became more variable over time, as the monsoon’s influence weakened, coinciding with enhanced Northern Hemisphere polar ice cover during the Pleistocene. Wetter conditions likely facilitated mammalian dispersals between Africa and Eurasia, with Arabia acting as a key crossroads for continental-scale biogeographic exchanges.

Abstract We document an apparent downward displacement of the Matuyama‐Brunhes magnetic reversal by ∼20 m at Scotia Sea International Ocean Discovery Program Site U1538 (Pirie Basin) by comparison with the well‐defined paleomagnetic record at nearby Site U1537 (Dove Basin). Detailed stratigraphic correlation between the two sites is possible due to similar lithologic variations. However, the two sites have distinctly different porewater geochemistry. Notably, Site U1538 indicates a greater demand for electron acceptors to oxidize organic carbon and Fe2+ enrichment below the depth of SO42− depletion. Magnetic parameters indicate enrichment of an authigenic magnetic mineral with strong remanence properties around the depth of SO42− depletion (∼46 m at Site U1538) relative to magnetic parameters at correlative depths at Site U1537. Fe2+ enrichment below the depth of SO42− depletion is not predicted based on the energetically favorable order of electron acceptors for microbial respiration but is documented here and in other depositional settings. This indicates Fe2+ production exceeds the production of H2S by SO42− reduction, providing a geochemical environment that favors the production and preservation of ferrimagnetic remanence‐bearing iron sulfides over paramagnetic pyrite and, thus, a mechanism for deep chemical remanent magnetization acquisition at depths of tens of meters. The influence of authigenic ferrimagnetic iron sulfides on paleomagnetic signals can be difficult to demonstrate with magnetic properties alone; therefore, this finding has implications for evaluating the fidelity of magnetostratigraphic records with complementary geochemical data. Such situations should be considered in other depositional environments with similar porewater Fe2+ accumulation below the SO42− reduction depth.

The investigation of triggers causing the onset and intensification of Northern Hemisphere Glaciation (NHG) during the late Pliocene is essential for understanding the global climate system, with important implications for projecting future climate changes. Despite their critical roles in the global climate system, influences of land-ocean interactions on high-latitude ice sheets remain largely unexplored. Here, we present a high-resolution Asian dust record from Ocean Drilling Program Site 1208 in the North Pacific, which lies along the main route of the westerlies. Our data indicate that atmosphere-land-ocean interactions affected aeolian dust emissions through modulating moisture and vegetation in dust source regions, highlighting a critical role of terrestrial systems in initiating the NHG as early as 3.6 Myr ago. Combined with additional multi-proxy and model results, we further show that westerly wind strength was enhanced, mainly at low-to-middle tropospheric levels, during major glacial events at about 3.3 and 2.7 Myr ago. We suggest that coupled responses of Earth’s surface dynamics and atmospheric circulation in the Plio-Pleistocene likely involved feedbacks related to changes in paleogeography, ocean circulation, and global climate. North Pacific dust flux and modelling results provide new evidence for long-term land-atmosphere-ocean interactions associated with the onset and intensification of the Northern Hemisphere Glaciation.

Mean Sortable Silt sic size records in the hemipelagic deposits at Site U1452 (IODP 354) in the lower Bengal Fan are presented here to reconstruct the bottom water circulation strengths in the Bay of Bengal (BoB) during the last 200 ka (Marine Isotopic Stage 1 to 6). To eliminate possible amplitude shifts in sic size due to terrestrial sediment flux or turbiditic interventions, sedimentation history at the site is decomposed using End Member Analysis (EMA). sic size record in the BoB is mostly unimpacted by the terrestrial sediment flux and turbidity current deposition; hence the size sorting signature in SS records is best described to have arisen from benthic boundary layer current intensity. sic size record in the BoB indicates reduced bottom water flow speed during glacials (MIS 2 and 6), concomitant with the greater import of Antarctic/Southern Ocean (SO) derived deep waters and increased speed during interglacials (MIS 1, 3 and 5) corresponding to an increased proportion of Northern Atlantic derived deep water mass in the northern Indian Ocean. Glacial and stadial decline in flow speed reflects on the density reversal between two deep water mass end members in the SO and a shoaled Atlantic meridional overturning circulation (AMOC). On the other hand, faster flow speed during the climate optima at MIS 5.5 and other warm substages of MIS 5 as well as during the Holocene present a deep and strong AMOC. Reduced bottom water circulation strength in the BoB during the MIS 5.5 to 5.4 transition might have contributed to atmospheric CO2 draw down and global cooling during the early stages of glacial inception along with deep circulation changes in the SO. Also, millennial-scale variability in circulation strength in the BoB is linked to oceanic frontal shift in high northern latitudes and deepwater formation manifesting in reduced flow strength associated with local cold anomalies (C28-C23), successively culminating into glacial inception at MIS 5.4. Reduced flow speed is also observed during some of the Heinrich events indicating a strong teleconnection between deep North Atlantic and BoB. Productivity changes in the BoB might as well have been influenced by variable fluxes of northern and southern sourced water mass during the last 200 ka.

Abstract High-resolution ice core records from coastal Antarctica are particularly useful to inform our understanding of environmental changes and their drivers. Here, we present a decadally resolved record of sea-salt sodium (a proxy for open-ocean area) and non-sea salt calcium (a proxy for continental dust) from the well-dated Roosevelt Island Climate Evolution (RICE) core, focusing on the time period between 40–26 ka BP. The RICE dust record exhibits an abrupt shift towards a higher mean dust concentration at 32 ka BP. Investigating existing ice-core records, we find this shift is a prominent feature across Antarctica. We propose that this shift is linked to an equatorward displacement of Southern Hemisphere westerly winds. Subsequent to the wind shift, data suggest a weakening of Southern Ocean upwelling and a decline of atmospheric CO2 to lower glacial values, hence making this shift an important glacial climate event with potentially important insights for future projections.

The Bengal Fan covers the entire floor of the Bay of Bengal (BoB) and has accumulated erosional material from the Himalayas since the Early Eocene. The fan architecture is constructed by turbidity current deposits via channel levee systems during active fan progradation and hemipelagic sedimentation during periods of local fan inactivity. In the present study, we document the fan development, sedimentation history, and depositional processes in the lower Bengal Fan and present a site-to-site comparison of stratigraphy and channel migration since the Late Tortonian (ca. 7.5 Ma) from sedimentological and physical property records at Site U1451 of IODP Expedition 354 to 8°N in the lower Bengal Fan. Fine sediment (Sortable Silt, SS) textural and sorting records are used to reconstruct the current skinfriction shear stress in the Benthic Boundary Layer (BBL) of the BoB. Also, a distinction in shear stress environment between turbidity dominated active fan and background hemipelagic fan growth is presented. A criterion is set in the following paper to validate the use of SS records in hemipelagic deposits in the BoB to decipher the shear stress regimes of depositing flows on the basis of sand weight percentage and mean SS sizes ( S͞S ) variation. This study will enhance our understanding of the Bengal Fan deposition dynamics and fan development with the reconstructed shear stre ss regimes associated with various depositing flows (turbidity current and/or deep water circulation). It will provide a strong base to model fan internal processes and material flux to the BoB.

We present a novel three-dimensional model of compressional wave attenuation (1/ Q P ) for the Eastern and eastern Southern Alps in Europe that includes the eastern part of the Adriatic indenter, termed here the Dolomites Sub-Indenter. Our approach employed waveform data from the SWATH-D network, a dense temporary network operational between 2017 and 2019, as well as selected stations of the larger AlpArray Seismic Network. A spectral inversion method using frequency-independent quality factor Q P , was applied to derive 3578 path-averaged attenuation values ( t* ) from 126 local earthquakes. These were then inverted using the damped least square inversion (local earthquake tomography) for the attenuation structure. The resulting Q P model, which builds on and complements a previously calculated 3-D velocity model ( V P and V P / V S ), exhibits good resolution down to ~ 20 km depth. Several anomalies can be correlated with the distribution of other physical parameters ( V P and V P / V S ) and regional tectonic features. Notably, the Friuli-Venetian region exhibits the highest attenuation (lowest Q P ) anomaly, coinciding with low V P values and increased V P / V S . This anomaly is likely associated with a high density of faults and fractures, as well as the presence of fluid-filled sediments along the active thrust front in the eastern segment of the Southern Alps. Another intriguing observation is the low attenuation (high Q P ) anomaly along the northwestern edge of the Dolomites Sub-Indenter (NWDI), located south of the Periadriatic fault and east of the Giudicarie fault, where seismicity is notably absent. This anomaly coincides with Permian magmatic rocks at the surface and may be a measure of their strength at depth. Graphical Abstract

Early Pleistocene Marine Isotope Stage (MIS)‐31 (1.081–1.062 Ma) is a unique interval of extreme global warming, including evidence of a West Antarctic Ice Sheet (WAIS) collapse. Here we present a new 1,000‐year resolution, spanning 1.110–1.030 Ma, diatom‐based reconstruction of primary productivity, relative sea surface temperature changes, sea‐ice proximity/open ocean conditions and diatom species absolute abundances during MIS‐31, from the Scotia Sea (59°S) using deep‐sea sediments collected during International Ocean Discovery Program (IODP) Expedition 382. The lower Jaramillo magnetic reversal (base of C1r.1n, 1.071 Ma) provides a robust and independent time‐stratigraphic marker to correlate records from other drill cores in the Antarctic Zone of the Southern Ocean (AZSO). An increase in open ocean species Fragilariopsis kerguelensis in early MIS‐31 at 53°S (Ocean Drilling Program Site 1,094) correlates with increased obliquity forcing, whereas at 59°S (IODP Site U1537; this study) three progressively increasing, successive peaks in the relative abundance of F. kerguelensis correlate with Southern Hemisphere‐phased precession pacing. These observations reveal a complex pattern of ocean temperature change and sustained sea surface temperature increase lasting longer than a precession cycle within the Atlantic sector of the AZSO. Timing of an inferred WAIS collapse is consistent with delayed warmth (possibly driven by sea‐ice dynamics) in the southern AZSO, supporting models that indicate WAIS sensitivity to local sub‐ice shelf melting. Anthropogenically enhanced impingement of relatively warm water beneath the ice shelves today highlights the importance of understanding dynamic responses of the WAIS during MIS‐31, a warmer than Holocene interglacial.

Antarctica is one of the most vulnerable regions to climate change on Earth and studying the past and present responses of this polar marine ecosystem to environmental change is a matter of urgency. Sedimentary ancient DNA (sedaDNA) analysis can provide such insights into past ecosystem-wide changes. Here we present authenticated (through extensive contamination control and sedaDNA damage analysis) metagenomic marine eukaryote sedaDNA from the Scotia Sea region acquired during IODP Expedition 382. We also provide a marine eukaryote sedaDNA record of ~1 Mio. years and diatom and chlorophyte sedaDNA dating back to ~540 ka (using taxonomic marker genes SSU, LSU, psbO). We find evidence of warm phases being associated with high relative diatom abundance, and a marked transition from diatoms comprising <10% of all eukaryotes prior to ~14.5 ka, to ~50% after this time, i.e., following Meltwater Pulse 1A, alongside a composition change from sea-ice to open-ocean species. Our study demonstrates that sedaDNA tools can be expanded to hundreds of thousands of years, opening the pathway to the study of ecosystem-wide marine shifts and paleo-productivity phases throughout multiple glacial-interglacial cycles.

In this study, 3‐D models of P‐wave velocity ( Vp ) and P‐wave and S‐wave ratio ( Vp / Vs ) of the crust and upper mantle in the Eastern and eastern Southern Alps (northern Italy and southern Austria) were calculated using local earthquake tomography (LET). The data set includes high‐quality arrival times from well‐constrained hypocenters observed by the dense, temporary seismic networks of the AlpArray AASN and SWATH‐D. The resolution of the LET was checked by synthetic tests and analysis of the model resolution matrix. The small inter‐station spacing (average of ∼15 km within the SWATH‐D network) allowed us to image crustal structure at unprecedented resolution across a key part of the Alps. The derived P velocity model revealed a highly heterogeneous crustal structure in the target area. One of the main findings is that the lower crust is thickened, forming a bulge at 30–50 km depth just south of and beneath the Periadriatic Fault and the Tauern Window. This indicates that the lower crust decoupled both from its mantle substratum as well as from its upper crust. The Moho, taken to be the iso‐velocity contour of Vp = 7.25 km/s, agrees with the Moho depth from previous studies in the European and Adriatic forelands. It is shallower on the Adriatic side than on the European side. This is interpreted to indicate that the European Plate is subducted beneath the Adriatic Plate in the Eastern and eastern Southern Alps.